Pond Liner Size Calculator

About this calculator

A rectangular pond liner needs to cover more than just the pond's footprint — it has to run down both side walls and across the bottom, plus leave extra material anchored beyond the edge. The standard formula is liner length = pond length + (2 × depth) + (2 × overlap), and the same for width, so a 3m × 2m pond that's 0.6m deep with a 0.3m overlap on each side needs a liner roughly 4.8m × 3.8m.

Landscapers and water-garden hobbyists building a koi pond, wildlife pond, or backyard water feature use this calculation before ordering liner material — EPDM rubber and PVC liners are typically sold by the roll or cut to custom size, and ordering short means an expensive reorder, while overestimating wastes material at a real cost per square metre.